I will just calculate maxed cyclone damage with max (10) stacks of DoV with Lolopanther 2H sword only equipped. Assuming enemy has 0 crit defense (or it’s crit defense is covered by gear).
I will compare full DEX, STR:DEX 4:3, STR:DEX 5:2 with STR:DEX 6:1 and full STR.
STR:DEX 5:2. Average Patk 2534(with Deeds and Gung Ho), Crit chance is 15.75%.
Cycolne will deal ((1355+2534)*1.5+625)*0.1575+(1355+2534)*0.8425=4293 average damage per hit. Attribute will affect DEX and STR indifferently.
STR:DEX 6:1. Patk 2708, crit chance is 8.1%.
Cyclone will deal ((1355+2708)*1.5+754)*0.081+(1355+2708)*0.919=4289 damage/hit.
STR. Patk 2874, crit chance 1.05%.
Cyclone will deal 4305 damage/hit.
STR:DEX 4:3. Patk 2362(huge drop), crit chance 23.25.
Cyclone will deal 4264 damage/hit.
DEX. Patk 1724, crit chance 54.9.
Damage 3934.
The result is: for the most benefical STR build you will get nearly the same damage with Full STR /Heavy STR builds and your damage will drop at >30% DEX. Interesting result is, that we have at least 2 peaks: the damage grows again near 5:2 mark. It would be nice to make a graph, but I 'm too lazy for this. Also adding monster gem/DM will obviously benefit DEX more.
Yet I should admit that for Highlander Cyclone is one of the most damaging skills so STR will really benefit other skills more. BUT I made calculations with full stacks of DoV. With not full stacks adding dex will actually increase DPS (because crit attack will matter more).
And for Barbarian adding DEX is even better, because he will get up to 400 bonus attack from Frenzy and his skills hit harder.
And lastly, Dex will additionally grant you some survivalbility over STR and more overkills. That’s all.

it makes sense archer concentrate on STR over DEX
so, gg. even the weapon i equipped not 2 hands sword, so its weaker